Select 2012-2013 survey findings – CBO meeting

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Transcript Select 2012-2013 survey findings – CBO meeting

Crane Survey Select Results from Recent Surveys Kampala, 2012/3 Men Who Have Sex With Men (MSM) Female Sex workers (FSW) Drug users Kampala, December 2013

Crane Survey

• Standing survey platform, Wandegeya • PEPFAR funded • Collaborative activity – Makerere University / School of Public Health – Ministry of Health – CDC

Key population HIV surveillance: Three pillars

• Surveys – How affected are they?

• Population size estimates – How many are they?

• Mapping – Where are they?

Bio-behavioral surveys

How affected are they?

Bio-behavioral survey design

• Sampling : Respondent-driven sampling – Participants refer others to survey – Facilitates population estimates: Survey findings apply to all key population members, not just those who participated – Anonymous (no names)

Bio-behavioral survey design (2)

• Data collection: audio-computer-assisted self interviews, facilitates more candid answers • Blood draw – HIV antibodies – CD4 cell count (disease stage) – Viral load: Number of viruses (“copies”) in blood – HIV results returned, HIV-positives referred

2012/3 Crane surveys

• Female sex workers (FSW) : 15+ years, sold sex to men in last 6 months • Men who have sex with men (MSM) : 18+ years, had anal sex with another man in last 6 months • Drug users (DUS) : 18+ years, habitual consumer of drugs in last 6 months (by nose, mouth, or injection) • All: residing in greater Kampala

Number of survey participants

• FSW: • MSM: 1,490 595 • DUS: 1,170

• FSW*: • MSM: • DUS:

HIV prevalence estimates (preliminary)

33% (Kampala general women: 9.5%) 13% (Kampala general men: 4.1%) 17% (Kampala general pop: 7.1%) • *) Note: Median duration of sex work at time of survey participation: 2 years

Select MSM characteristics

• Syphilis prevalence: • Ever tested for HIV: • HIV prevalence: • Self-reported on ART: 3% 70% 13% 14% (among HIV-pos)

CD4 cell count

• Average: 406 • 50% between: 300–520 • CD4<350: ~27%*

Viral load

• Average: 37,000 copies / ml • 50% between: 8,000–120,000 • Suppressed (<1000): ~11%* *) Small numbers – unstable estimates

Select FSW characteristics

• Syphilis prevalence: • HIV prevalence: • Self-reported on ART 6% 33% 18% (among HIV-pos)

CD4 cell count

• Average: 443 cells / ul • 50% between 300–600 • CD4<350: 32% (of these, 86% not on ART)

Viral load

• Average: 3,500 copies / ml • 50% between: 100–38,000 • Suppressed (<1000): 37%

High rates of gender-based violence (GBV) among Kampala FSW

• 49% ever experienced rape – Rape defined as the use of force or threat to use force – Of those who have ever been raped, on average report having been raped twice in last 6 months (50% range: 1-3) • 82% exposed to some form of GBV in last 6 months – Defined as: physical abuse, verbal abuse, forced sex acts, paid less or not paid at all after sex act – 52% experienced three or more GBV events in last 6 months

Conclusion - FSW

• Very high HIV prevalence among FSW: 33% – 3x that of Kampala women in general – One in three HIV-pos FSW with CD4 <350 – Short average duration of sex work at time of survey participation suggests: • high turn-over • high HIV incidence • warrants frequent outreach services

Conclusion – MSM, drug users

• MSM: HIV prevalence 13% – triple that of Kampala men in general – low self-reported ART uptake – high average viral load (high forward transmission potential) – small proportion with suppressed viral load • Drug users: HIV prevalence 17% – more than double that of general population in Kampala

Population size estimates

How many are there?

Objective

• To estimate the population sizes of – Female sex workers (FSW) – Men who have sex with men (MSM) in Kampala, Uganda

Method to estimate population size: Capture/recapture

Universe: (e.g., all sex workers in Kampala)

N

Sex workers captured twice (“Match”)

Sex workers captured, e.g., with key chains (Sample 1) C 1 M Sex workers recaptured, e.g., by survey (Sample 2) N = C 1 * C 2 / M C 2

Capture 1 – tagging key pop members with a small gift

• Ordered several hundred tailor-made key chains – Not available commercially • Distributed by community members – 540 key chains among FSW – 400 key chains among MSM

Capture 2 - survey

• Respondent-driven sampling survey (RDS) • Start: after key chain distribution • Asked every participant if s/he can –

show key chain

or –

identify key chain

(received but doesn’t have) • Had to choose correct key chain out of 6 similar key chains • “Match” defined as survey participant who show or identified correct key chain

Population size estimates – Match: presenting or identifying correct key chain • FSW: • MSM: 13,200 (95% CI: 10,200 – 16,200) 7,900 (95% CI: 4,400 – 11,300) • Kampala 15-59 population: ~800,000 (49% male)* + – Proportion FSW: 3.3% (2.5% - 4.0%) – Proportion MSM: 2.0% (1.1% - 2.9%) *): Source: UBOS: 1.73M in 2012, assumed proportion <15 yrs: 49%, assumed sex distribution: 50%. http://www.ubos.org/onlinefiles/uploads/ubos/pdf%20documents/abstracts/2012%20Statistical%20Ab + ) : Note: Age bands not identical to MSM survey eligibility age criteria

Conclusion – FSW and MSM size estimates for Kampala

• Conservative estimate: – MSM: – FSW: 8,000 (95% CI: 4,000 - 11,000) 13,000 (95% CI: 10,000 - 16,000) – Note: FSW highly mobile, both • Occupationally (in and out migration of sex work) • Geographically (change in sex work location)

Linking size estimation and mapping

Where are they?

Crane survey – virtual, electronic mapping of key populations

• Respondents: • Interview location: • Software: • Mapping results: Survey participants (MSM, FSW) Survey office Google Earth (offline) Geo-social locations, i.e., where - FSW respondents meet clients - MSM socialize • Note: mapping of (transient) individual geo-social locations, not primarily venues / buildings

Geo-social locations of sex workers Makindye “About 200 sex workers hang out at G8 club,…, especially on the weekends.” (Venue names changed by investigators)

Using

GIS software

to identify and characterize clusters of sex workers

Color

: population size (darker ~ larger)

Size

: geographic extent of cluster

Projecting Kampala’s FSW population size estimate (13,000) to the relative sizes of mapped clusters

Thank you

George Lubwama, Enos Sande (SPH / Makerere University) Rachel Kwezi, Sam Sendagala, Michael Ediau (CDC Uganda) Steven Borders (GIS Corps) Wolfgang Hladik, Drew Baughman, Jim Tobias (CDC Atlanta)

Using GIS software to characterize clusters of sex workers Color: population size (darker ~ larger) Size: geographic size of cluster

“Mapping and Size Estimation of the Key Affected Populations in Kampala Capital City Authority”, 2013 • Method: Census (?) • FSW: 2,148 (95% CI: 1,611-2,685) • MSM: 253 (95% CI: 169-338) • Note: Crane MSM Survey 2012/3, sample size: 595 Commissioned work by D Muhangi and J Kiwanuka for: Alliance of Mayors and Municipal leaders on HIV/AIDS in Africa

Modes of Transmission study

• UNAIDS commissioned report, 2009 • Country-wide estimates – FSW (last 12 months): 32,652 – MSM: 3,976

Future size estimation activity: Network scale-up

• Population size estimation through general population based survey – Nation-wide – Sample size ~5,000 adults • Size estimates for MSM, MSW, FSW, PWID, ‘mobile men with money’ • Strata: Kampala, urban, rural • Start early 2014

Past population size estimates lack quality data sources: Modes of Transmission study (2009) National size estimates • FSW : Sex for money in last 12 months: – Number: 32,652 (projected % value from abroad) – Proportion: 0.3% • MSM: (No operational definition) – Number: – Proportion: 4,000 ( “MSM study expert guess x 2”) <0.1%

Assumptions

1. Closed population 2. Everyone has equal, non-zero sampling probability 3. Capture and recapture constitute independent samples (no correlation) 4. Matches are accurate In practice, hard to meet all assumptions

Summary

Capture 1 Capture 2 Matches, total Matches, present** Matches, identify***

FSW

540 1567 64 30 34

MSM

380 (400)* 372 18 *Approximately 20 UMOs distributed “late”, i.e., during RDS sampling period (excluded from analysis) ** presented UMO *** did not present, but did identify correct UMO 6 12

Population size estimates - Match: presenting correct key chain • FSW: • MSM: 26,000 (95% CI: 18,000 – 35,000) 28,000 (95% CI: 4,000 – 53,000) *): Source: UBOS: 1.73M in 2012, assumed proportion <15 yrs: 49%, assumed sex distribution: 50%. http://www.ubos.org/onlinefiles/uploads/ubos/pdf%20documents/abstracts/2012%20Statistical%20Abstract.pdf